This invention relates to tubular remote controls in which a push-pull blade is movable lengthwise in the tubular member of the control while the blade is supported on each of its opposite sides by a series of spaced rolling elements.
Illustrative of such a remote control is that disclosed in U.S. Pat. No. 3,287,990 to Ellinger wherein the bearing balls of each of two series are held spaced along the push-pull blade by a cage strip. U.S. Pat. No. 4,062,251 to Parsons reveals an intricate ball-cage strip and a costly machine for making the ball-cage strip. U.S. Pat. No. 3,667,313 to Young shows a simplified ball-cage strip.
Obviously, the two cage strips on opposite sides of the push-pull blade add to the cost and weight of the remote control. Furthermore, the cage strips occupy space and thus make it necessary to have a tubular sheath with a diameter larger than would be required if the cage strips were not present. Thus, the remote control has a sheath or conduit of larger diameter, weight and cost than would be the case if the two cage strips were eliminated.
Moreover, inasmuch as both cage strips move each time the push-pull blade is moved, the remote control has three movable elongate members each of which is susceptible to wear, damage and malfunction from reciprocating the push-pull blade over a long period of time. Clearly, a remote control in which the push-pull blade is the sole movable elongate member is highly desirable.
Accordingly, the object of this invention is to eliminate the two cage strips in a remote control by providing the push-pull blade with openings spaced along its length which are dimensioned to hold rolling elements on opposite sides of the blade in rolling contact with each other.